Patent literature 1: JP 2013-048524 A
Conventionally, a control apparatus of a rotary machine is known. The control apparatus includes electric power converters in multiple systems and controls energization to corresponding multiple winding groups. When either of the systems gets out of order, the control apparatus drives the rotary machine only with an electric power converter and a winding group in a normal system is known.
For example, a control apparatus for a multiple-phase rotary machine described in patent literature 1 controls an output of electric power converter when a short circuit failure occurs in an electric power converter or a winding group in either one of two systems. In this case, the control apparatus in patent literature 1 stops an output to an electric power converter of a failure system and sets an output limit value of the output to an electric power converter of a normal system smaller as the rotation number of the rotary machine is greater. The processing is performed in order to prevent the electric power converter and the winding wire in the failure system from excessively generating heat due to a counter electromotive voltage generated in the failure system accompanied with a rotation of the rotary machine.
The inventors of the present disclosure have found the following.
When a shirt circuit failure occurs in one of systems, a braking torque against a driving may generate in the rotary machine due to the counter electromotive voltage, which is generated in the failure system accompanied with the rotation of the rotary machine. Thus, at the time of the driving only with the normal system, so that the rotary machine outputs a required torque similar to a normal driving condition, it may be necessary to send current to the electronic power converter in the normal system greater than the normal driving condition for compensating the lowering of the torque by the braking torque. Incidentally, the normal driving condition is a condition where the two systems function normally.
Patent literature 1 may focus on a prevention of heat generation in the failure system.